Question

Which of the following reactions is not correct?

• A. $MnO_{4}^{-} + 8H^{+} + 5e^{2 +} \rightarrow 5Fe^{3 +} + Mn^{2 +} + 4H_{2}O$
• B. $2MnO_{2} + 4KOH + O_{2} \rightarrow 4KMnO_{4} + 2H_{2}O$
• C. $2Na_{2}CrO_{4} + 2H^{+} \rightarrow Na_{2}Cr_{2}O_{7} + 2Na^{+} + H_{2}O$
• D. $K_{2}Cr_{2}O_{7} + 7H_{2}SO_{4} + 6KI \rightarrow 4K_{2}SO_{4}$$$ + Cr_{2}(SO_{4}){3} + 3I{2} + 7H_{2}O$$

Answer 1

Answer: (B)

$2MnO_{2} + 4KOH + O_{2} \rightarrow 4KMnO_{4} + 2H_{2}O$

Answer 2

$2MnO_{2} + 4KOH + O_{2} \rightarrow 2K_{2}MnO_{4} + 2H_{2}O$